The objectives of this investigation were to (a) participate in a cooperative cyclic triaxial testing program with seven other laboratories and (b) determine the effect of various testing techniques and equipment, i.e., specimen preparation and compaction, B value, density, loading wave from, and compaction equipment on the cyclic triaxial strength of a sand. A total of 28 saturated isotropically consolidated-undrained cyclictriaxial tests were conducted on 2.8i-n.-diam by 7-in.-high specimens of Monterey No. 0 sand. Specimens were compacted to 60 percent relative density (89.5 pcf) using three different compaction techniques (i.e. dry rodding, moist rodding, and moist tamping) with some instances of undercompacting the lower layers. Some specimens were compacted to a relative density of about 66 percent while others were tested when the B value reached approximately 0.91. The effect of loading wave shape was evaluated by subjecting specimens to either a rectangular, near triangular, or sinusolidal loading wave from. It was found that if careful attention was given to testing details, good agreement could be obtained by different testing laboratories. The test results also demonstrated that the cyclic triaxial strength is greatly influenced by the method of specimen compaction, density, and shape of loading wave. Specimens prepared moist, either rodded or tamped, were 38-58 percent stronger than comparable specimenscompacted dry to the same relative density. A 12 percent increase in the relative density was sufficient to cause an increase in strength of approximately 22-30 percent. Furthermore, the severity of loading wave from on the cyclic triaxial strength was found to decrease in the following order: square, nearly triangular, and sine, with strength differences of 13 to 30 percent being due to the loading wave shape. The test results also showed that for this sand, changing the diameter of the compaction foot, decreasing the molding water content from 12.8 to 8.0 percent, or testing specimens with a B value of 0.98 or 0.91 had no significant effect on the cyclic triaxial strength of specimens.

  • Corporate Authors:

    U.S. Army Waterways Experiment Station

    3909 Halls Ferry Road
    Vicksburg, MS  United States  39180-6199
  • Authors:
    • Mulilis, J P
    • Horz Jr, R C
    • Townsend, F C
  • Publication Date: 1976-4

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 40 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00139179
  • Record Type: Publication
  • Report/Paper Numbers: S-76-7 Final Rpt.
  • Files: TRIS
  • Created Date: Sep 4 1976 12:00AM